The invention relates to a connecting lock for tire chains with an elongate receiving opening for receiving two chain links, wherein the receiving opening is framed by a first continuous longitudinal crosspiece, by a second, opposed longitudinal crosspiece interrupted by an insertion opening, and by two transverse crosspieces, and the chain links in the receiving opening are secured from sliding out by means of a closing bolt, which can be inserted via one end into a bore in the first longitudinal crosspiece and is directed via its second, free end toward the insertion opening in the second longitudinal crosspiece.
A connecting lock of this type is disclosed for example in DE 16 05 670 B2. With this known connecting lock, the closing bolt is a spiral locking pin, which is inserted into the bore, formed as a through-bore, in the first longitudinal crosspiece in order to secure the chain links. However, if the application of force for insertion of the locking pin is high, a hammer is required for this purpose and there is a significant risk of damage as a result of splintering of the spiral locking pin as it is driven into the bore. The disassembly of the lock by removal of the spiral locking pin is also problematic, since the pin has to be removed with the aid of a hammer and a punch. In practice, the spiral locking pin is often so corroded however that the connecting lock has to be cut through using a blowtorch in order to release the chain links.
Another connecting link of the objective type has become known from DE 765 176 B. With this connecting link, the closing bolt is mounted displaceably in the bore in the first longitudinal crosspiece and it carries on its outer end facing the tread of a vehicle tire a widening in the form of a head, which bears against the tread during use so that the bolt is held in a locked position and the chain links are secured from sliding out from the connecting lock. A disadvantage of this solution is the fact that, with looser chains, it is not ensured that the head of the closing bolt will bear against the tread, and therefore the bolt may slip and the chain links may be released in an undesired manner.